1993 CHEVROLET DYNASTY sensor

WIRING DIAGRAMS AA-BODY
INDEX
Wiring Diagram Name Sheet Number
Anti-Lock Brake System.................41, 42, 43, 44
ABS Pump Motor Relay.......................41
ABS System Relay..........................43
Brake Switch..............................44
Controller.....................41, 42, 43, 44, 114
Data Link Connector.........................44Wiring Diagram Name Sheet Number
Diode-Warning Lamp.........................43
Hydraulic Modulator.........................41
Ignition Switch.............................44
Park Brake Switch...........................44
Wheel Sensors.............................42
ÄWIRING DIAGRAMS AA-BODY 8W - 1

WIRING DIAGRAMS AJ BODY
ALPHABETICAL INDEX
Wiring Diagram Name Sheet Number
Anti-Lock Brake System.................68, 69, 70, 71
ABS Controller..................68, 69, 70, 71, 170
ABS Hydraulic Modulator......................68
ABS Pump Motor Relay.......................68
ABS System Relay..........................69
ABS Warning Lamp Diode......................69
ABS Warning Switch Lamp Switch................70Wiring Diagram Name Sheet Number
Brake Switch..............................70
Data Link Connector.........................70
Left Front Wheel Sensor.......................71
Left Rear Wheel Sensor.......................71
Park Brake Switch...........................70
Right Front Wheel Sensor......................71
Right Rear Wheel Sensor......................71
8W - 8 WIRING DIAGRAMS AJ BODYÄ

COMPONENT AND SYSTEM INDEX
Name Group-page Name Group-page
BRAKES ..................................5-1
BENDIX ANTILOCK 4 BRAKE SYSTEM ...........5-12
ABS BRAKE SYSTEM DIAGNOSTIC FEATURES.......5-24
ABS SYSTEM SELF DIAGNOSIS................ 5-24
BENDIX ANTILOCK 4 BRAKE SYSTEM DIAGNOSTICS....5-25
CONTROLLER ANTILOCK BRAKE CAB............. 5-24
LATCHING VERSUS NON-LATCHING ABS FAULTS.......5-25
START-UP CYCLE........................ 5-24
ABS COMPUTER SYSTEM SERVICE PRECAUTIONS....5-23
ABS GENERAL SERVICE PRECAUTIONS........... 5-23
ABS BRAKE SYSTEM ON VEHICLE SERVICE.........5-23
TEST DRIVING ABS COMPLAINT VEHICLES.......... 5-23
WHEEL SPEED SENSOR CABLES............... 5-23
ANTILOCK BRAKE SYSTEM COMPONENTS..........5-16
BUILD/DECAY VALVES..................... 5-16
FLUID SUMPS.......................... 5-17
HYDRAULIC SPRING ACCUMULATOR.............5-17
MODULATOR ASSEMBLY.................... 5-16
PRESSURE DIFFERENTIAL SWITCH..............5-17
PROPORTIONING VALVES................... 5-17
PUMP/MOTOR ASSEMBLY...................5-17
SHUTTLE ORIFICE........................ 5-16
WHEEL SPEED SENSORS....................5-18
ANTILOCK BRAKE SYSTEM DEFINITIONS..........5-14
ANTILOCK BRAKES OPERATION AND PERFORMANCE. . . 5-15
ANTILOCK BRAKE SYSTEM OPERATION............ 5-15
PEDAL FEEL........................... 5-15
TIRE NOISE & MARKS.....................5-15
ANTILOCK SYSTEM RELAYS AND WARNING LAMPS. . . 5-19
ANTILOCK WARNING LAMP DIODE..............5-20
Antilock Warning Lamp Off................... 5-20
Antilock Warning Lamp On...................5-20
PUMP/MOTOR RELAY...................... 5-20
SYSTEM RELAY......................... 5-19
BENDIX ANTILOCK 4 BRAKE SYSTEM DIAGNOSTICS. . . 5-22
DEFINITIONS........................... 5-23
GENERAL INFORMATION....................5-22
BLEEDING BENDIX ANTILOCK 4 BRAKE SYSTEM......5-25
BENDIX ANTILOCK 4 MODULATOR ASSEMBLY BLEEDING
PROCEDURE
......................... 5-26
HYDRAULIC BRAKE TUBE ASSEMBLY (JUNCTION BLOCK
TO MODULATOR ASSEMBLY)
................ 5-34
INSTALL............................ 5-36
REMOVE............................5-34
MASTER CYLINDER AND POWER BOOSTER.........5-38
REMOVAL AND INSTALLATION................. 5-38
MODULATOR ASSEMBLY CIRCUIT BLEEDING PROCEDURE
AND SEQUENCE
....................... 5-26
1 MODULATOR PRIMARY CHECK VALVE CIRCUIT........5-26
2 MODULATOR SECONDARY CHECK VALVE CIRCUIT......5-26
3 MODULATOR ASSEMBLY PRIMARY SUMP CIRCUIT......5-27
4 MODULATOR ASSEMBLY PRIMARY ACCUMULATOR CIRCUIT. 5-27
5 MODULATOR ASSEMBLY SECONDARY SUMP CIRCUIT....5-28
6 MODULATOR ASSEMBLY SECONDARY ACCUMULATOR
CIRCUIT
........................... 5-29
MODULATOR ASSEMBLY (FIG. 1)...............5-30
INSTALL............................ 5-32
REMOVE............................5-30
PROPORTIONING VALVES (FIG. 1)...............5-38
INSTALL............................ 5-39
REMOVAL...........................5-38
PUMP/MOTOR SERVICE....................5-29
CONTROLLER ANTILOCK BRAKE CAB.............5-18
CONTROLLER ANTILOCK BRAKE (INPUTS)..........5-19
CONTROLLER ANTILOCK BRAKE (OUTPUTS).........5-19
DIAGNOSTIC CONNECTOR.................... 5-19
ELECTRONIC COMPONENTS..................5-41
CONTROLLER ANTILOCK BRAKE CAB.............5-41
INSTALL............................ 5-42
REMOVE............................5-41
FRONT WHEEL SPEED SENSOR (FIG. 9)...........5-43
INSTALLATION......................... 5-44
REMOVAL........................... 5-43
REAR WHEEL SPEED SENSOR (FIGS. 10 AND 11)......5-44
INSTALLATION......................... 5-44
REMOVAL........................... 5-44
REMOVAL/INSTALLATION OF SYSTEM RELAY.........5-42
INSTALL............................ 5-43
REMOVE............................5-43
REMOVE/INSTALL PUMP MOTOR RELAY...........5-43
WHEEL SPEED SENSORS.................... 5-43
INSPECTION.......................... 5-43
GENERAL INFORMATION....................5-12
HYDRAULIC CIRCUITS AND VALVE OPERATION......5-20
ABS BRAKING-BUILD PRESSURE............... 5-20
BUILD/DECAY VALVES..................... 5-20
ABS BRAKING-DECAY PRESSURE...............5-22
BUILD/DECAY VALVES..................... 5-22
NORMAL BRAKING....................... 5-20
BUILD/DECAY VALVES.....................5-20
MAJOR COMPONENTS...................... 5-14
CONTROLLER ANTILOCK BRAKE CAB.............5-14
MASTER CYLINDER AND VACUUM BOOSTER.........5-14
MODULATOR AND PUMP MOTOR/ASSEMBLY.........5-14
WHEEL SPEED SENSORS.................... 5-14
MECHANICAL DIAGNOSTICS AND SERVICE
PROCEDURES
.......................... 5-24
INTERMITTENT FAULTS.....................5-24
SPECIAL SERVICE TOOL....................5-24
DRB DIAGNOSTIC TESTER...................5-24
NORMAL BRAKE SYSTEM FUNCTION.............5-14
ON-CAR ABS BRAKE SYSTEM SERVICE...........5-25
CHECKING BRAKE FLUID LEVEL................ 5-25
GENERAL SERVICE PRECAUTIONS...............5-25
SPECIFICATIONS......................... 5-46
SYSTEM SELF-DIAGNOSTICS..................5-15
VEHICLE PERFORMANCE.................... 5-15
WARNING SYSTEMS OPERATION...............5-16
NORMAL OPERATION OF WARNING LAMP..........5-16
GENERAL INFORMATION .....................5-1
HYDRAULIC SYSTEM CONTROL VALVES .........5-10
GENERAL INFORMATION.................... 5-10
HYDRAULIC SYSTEM SERVICE PROCEDURES........5-11
BRAKE WARNING SYSTEM................... 5-11
CHECKING BRAKE WARNING SWITCH UNIT...........5-11
TESTING ANTILOCK PROPORTIONING VALVES........5-11
PRESSURE DIFFERENTIAL WARNING LIGHT SWITCH. . . 5-10
SERVICE ADJUSTMENTS .....................5-3

tifreeze to achieve adequate protection. A mix table
on the coolant container indicates the amount of an-
tifreeze required to winterize the cooling system
based on the capacity, see Capacity Chart in General
Information section of this group.
SELECTING ANTIFREEZE
Chrysler Corporation recommends Mopar Anti-
freeze/Summer Coolant, or equivalent be used to win-
terize and protect cooling system.
RADIATOR CAP
The radiator cap must be secure to provide proper
pressure release and coolant recovery. Inspect and
test radiator cap when cooling system service is per-
formed or when problem is suspected.
COOLING SYSTEM SERVICE
The cooling system should be drained, flushed and
filled with the proper coolant mixture at the inter-
vals described in the Lubrication and Maintenance
Schedules. Refer to General Information section of
this group. For proper service instructions see Group
7, Cooling System.
ENGINE AIR CLEANER
The engine air cleaner should be serviced at the in-
tervals described in the Lubrication and Mainte-
nance Schedules. Refer to General Information
section of this group. Additional information can be
found in Group 14, Fuel System and Group 25, Emis-
sion System. Inspect all air cleaner hoses or tubes for
damage or leaks when other engine compartment
service is performed. Replace faulty components.
AIR CLEANER SERVICE
CAUTION: The air cleaner cover must be installed
properly for the emissions system and engine con-
troller to function correctly. Do not immerse paper air filter element or temper-
ature sensor in cleaning solvents, damage can re-
sult.
TO SERVICE AIR CLEANER ASSEMBLY: (1) Raise hood of vehicle and inspect all air cleaner
components for damage or improper attachment. (2) Remove air cleaner cover (Fig. 6, 7, 8, 9, or 10).
(3) Remove paper air filter element from air
cleaner body. Hold a shop light on throttle body side
of element. Inspect air intake side of element. If light
is visible through element, blow dust from element
(Fig. 11) and reuse. If element is saturated with oil
or light is not visible, replace filter. If element is sat-
urated with oil, perform crankcase ventilation sys-
tem tests. (4) Remove fiber crankcase filter (Fig. 6, 7, 8, 9, or
10) and clean with solvent, squeeze filter dry and ap- ply small amount of engine oil. If a metallic mesh is
used to retain fiber filter, clean mesh with solvent
and reuse.
(5) Clean inside of air cleaner cover and body with
vacuum or compressed air. If oily, wash with solvent. To Install, reverse the preceding operation.
Fig. 6 Air CleanerÐ3.0L Engine
Fig. 7 Air CleanerÐFlexible Fuel Engine
Fig. 8 Air CleanerÐ16 Valve Engine
Ä LUBRICATION AND MAINTENANCE 0 - 11

AUTOMATIC AIR LOAD LEVELING SYSTEM INDEX
page page
Compressor Performance Test .............. 61
Compressor Relay ........................ 72
Control Module .......................... 72
General Information ....................... 59
Major Components ....................... 59 Rear Leveling Diagnostic Procedures
......... 65
Right Shock Absorber (With Height Sensor) .... 72
Service Procedures ....................... 62
System Operation ........................ 61
GENERAL INFORMATION
The automatic air load leveling system includes
the following (Fig. 1).:
² Compressor Assembly
² Control Module Wiring Harness
² Air Lines
² Compressor Relay
² Air Shock Absorbers
² Air Dryer
This system is used to supplement standard sus-
pension systems on vehicles so equipped.
MAJOR COMPONENTS
COMPRESSOR ASSEMBLY
The compressor assembly is driven by an electric
motor and supplies air pressure between 1172 to
1516 kPa (170 to 220 psi) (Fig. 2). A solenoid oper-
ated exhaust valve, located in the compressor head
assembly, releases air when energized.
CONTROL MODULE
The Control Module (CM) is a device that controls
the ground circuits for the compressor relay and the
exhaust valve solenoid. A microprocessor within the
module limits the compressor pump operation time to
140 to 160 seconds. To prevent damage to the com-
pressor motor.
Fig. 1 Automatic Air Load Leveling System
Ä SUSPENSION AND DRIVESHAFTS 2 - 59

In addition, there is an air regeneration cycle that
is controlled by the Control Module (CM). If the
height sensor signal is in the neutral or high posi-
tion. When the ignition switch is turned to the ON
position, after a 22 to 28 second delay, the compres-
sor will run from 2 to 6 seconds. To prevent excessive cycling between the compres-
sor and the exhaust solenoid circuits during normal
ride conditions. A 12 to 18 second delay is incorpo-
rated in the microprocessor.
HEIGHT SENSOR
A magnetic switch type sensor, located in the right
air shock absorber, monitors rear vehicle height. The
sensor sends signals to the (CM) relating to vehicle
rear suspension status (low, trim, high).
AIR LINES AND FITTINGS
To release an air supply line from a rear shock ab-
sorber assembly. Push in (toward shock absorber) on
the plastic ring of the shock absorber air line fitting.
Then while holding in the plastic ring on shock ab-
sorber fitting pull the air supply line strait out of fit-
ting (Fig. 3). The fitting has a unique push-in feature. A brass
type collet locks the air line in place. One rubber
O-ring seals the air line to prevent air leakage. To
attach air line, push into fitting (Fig. 4).
COMPRESSOR RELAY
The relay is mounted to a bracket on the Control
Module (CM). When the relay is energized, it allows
the compressor to operate. This unit is controlled by
the CM.
AIR ADJUSTABLE SHOCK ABSORBERS
Air shock absorbers are essentially hydraulic shock
absorbers with a neoprene bladder sealing upper and
lower sections together. This creates an air cylinder
inside of the shock absorber.
AIR DRYER
The air dryer is attached to the compressor. This
component serves two purposes; it absorbs moisture
from the atmosphere before it enters the system. And
with the internal valves maintains a residual system
pressure of 69 to 152 kPa (10 to 22 psi).
AIR CHECK, RESIDUAL (FIG. 5).
The air dryer has a valves arrangement that main-
tains 69 to 152 kPa (10 to 22 psi) in the air shocks.
This is to improve the ride characteristics of the ve-
hicle under light load conditions. To test this func-
tion, perform the following procedure: (1) Remove the air line from the dryer and right
shock absorber. Attach a piece of bulk nylon tubing
to one side of a Pressure Gauge (0-300 psi), and to
the right shock absorber (Fig. 5). (2) Attach another piece of nylon tubing from the
dryer (compressor) to other side of the pressure
gauge.
Fig. 2 Compressor AssemblyFig. 3 Release Air Line from Fitting
Fig. 4 Push Air Line into Fitting
2 - 60 SUSPENSION AND DRIVESHAFTS Ä

A compression ball sleeve nut and sleeve for 3/16
inch tubing with ball sleeve connector and an inter-
nal pipe T-fitting. Can be used to attach the tubing
to the pressure gauge. (3) Cycle ignition from OFF to ON.
(4) Apply a load to the rear of the vehicle (two as-
sistants or approximately 300-325 lbs.) to run com-
pressor and raise the vehicle. (5) Remove the load applied in Step 4. Allow the
system to exhaust and lower the vehicle. (6) When no more air can be exhausted, the gauge
should indicate 69 to 152 kPa (10 to 22 psi). (7) Remove the pressure gauge and nylon tubing.
Attach the air line between the dryer and shock ab-
sorber. Repeat Steps 3, 4, and 5 to ensure system air
pressure is in the shocks.
LEAK CHECKS
(1) Repeat Residual Air Check Steps 1, 2, 3, and 4.
Allow the system to fill until gauge reads 483 to 621
kPa (70 to 90 psi). If compressor is permitted to run until it reaches
its maximum output pressure, the vent solenoid
valve will function as a relief valve. The resulting
leak down, when compressor shuts off, will indicate a
false air leak. (2) With load still applied, disconnect wire harness
connector from the control module, then remove ap-
plied load. Vehicle should rise. Cycle ignition switch
to OFF. (3) Observe if pressure leaks down or holds steady
(wait approximately 15 minutes). (A) If system will not inflate beyond 345 kPa (50
psi). A severe leak may be indicated. Check for a
pinched pressure line between compressor and
shocks. (B) The standard soap solution check procedure is
acceptable. (C) If pressure holds steady, perform the diagnosis
procedures.
SYSTEM OPERATION
RAISING VEHICLE HEIGHT
When weight is added to the rear suspension. The
body of the vehicle is lowered, moving the height
sensor down. This action will activate the internal time delay
circuit. After a time delay of 12 to 18 seconds. The
control module (CM) activates the ground circuit to
the compressor relay. With the relay energized, the compressor motor
runs and air is sent through the system. As the
shock absorbers inflate, the body moves upward to a
corrected position. When the body reaches the correct
height, the control module (CM) stops the compressor
operation.
LOWERING VEHICLE HEIGHT
When the weight is removed from the vehicle. The
body moves upward, which allows the height sensor
to move upward and activate the internal time delay
circuit. After a time delay of 12 to 18 seconds. The (CM)
activates the exhaust solenoid circuit. Air is ex-
hausted from the shock absorbers through the air
dryer and exhaust solenoid to the atmosphere. As the body lowers, the height sensor is lowered to-
ward its original position. When the body reaches the
original vehicle height, the (CM) opens the exhaust
solenoid valve circuit.
COMPRESSOR PERFORMANCE TEST
This test can be performed on the vehicle. It is
used to evaluate compressor current draw, pressure
output, and leak down. (1) Disconnect the compressor motor wiring har-
ness connector. (2) Disconnect air line between dryer and right
shock absorber. (3) Connect an air pressure gauge into the system
(Fig. 5). (4) Connect an ammeter in series between the red
wire terminal on compressor connector and a 12 volt
power source. Also, connect a ground wire from the
black wire terminal on the compressor connector to a
good ground on the frame (Fig. 6). (5) If the current draw to the compressor motor ex-
ceeds 21 amperes, replace the compressor assembly. (6) When the air pressure stabilizes at 827 kPa
(120 psi), disconnect the (+) wire lead from the con-
nector. Replace the compressor assembly if any of the
following conditions exists:
Fig. 5 Pressure Gauge Installed in System
Ä SUSPENSION AND DRIVESHAFTS 2 - 61

REAR LEVELING DIAGNOSTIC PROCEDURES
SELF-DIAGNOSTICS
A self-diagnostic procedure is available for the ser-
vice technician to use to detect system malfunctions.
BEFORE DIAGNOSTICS TEST
Check the 20 amp fuse (position W40) and the 30
amp circuit breaker (position W5) to be assured they
are functional components. Check all connectors that link the system into the
main body wiring harness. These include compressor,
height sensor, control module, (Fig. 7) and relay.
Also check the underbody to in trunk and leveling
harness to main body harness connectors. Also, check
all air lines, connectors, and other components for
correct installation.
TEST LAMP PIN OPERATION
The monitor lamp pin output will be activated (test
lamp on) if the detection of abnormal system opera-
tion is determined by the CM.
AFTER COMPLETION OF REPAIRS
To initiate diagnostics, disconnect the test ground
wire then reconnect for repair verification.
TERMINATION OF SELF-DIAGNOSTICS
The self-diagnostic operation is terminated when
any of the following takes place:
² Disconnecting the diagnostic input from the
ground circuit.
² Turn the ignition switch to the off position.
When the self-diagnostic operation is terminated.
The control module resumes normal operation unless
it ceases operation. Due to it detecting a system mal-
function.
TEST WEIGHT
Weight between 275-300 lbs. must be added to rear
of vehicle before diagnostic testing begins.
DIAGNOSTICS (TO START PROCESS)
(1) Remove protective connector cover from diag-
nostic connector. (2) Insert wire into diagnostic ground pin. Then at-
tach to compressor ground pin, or as an alternate, in-
sert wire into diagnostic ground pin. Then ground
other end of test wire to body structure or a control
module fastener.
IGNITION
The following self diagnostic operation is initiated
by connecting the diagnostic ground pin to ground af-
ter ignition switch is turned ON. A monitor lamp
must be connected between the Test Lamp Ground
Pin and the Test Lamp Feed Pin to display the con-
trol module diagnostics status. See (Fig. 8) for diag-
nostic test pin locations.
OPERATION
(1) The compressor relay output. From the control
module (CM), is activated until the vehicle is in the
high position. The maximum relay output operation
time is 150 610 seconds. If the expected position is
not obtained, the CM ceases self-diagnostics and any
further operation. (I.e. neither operates the compres-
sor relay or exhaust outputs). The monitor lamp out-
put is continuously activated until ignition is cycled
from OFF to ON or 60 61 minutes has elapsed after
ignition was turned off. See Diagnostics Chart 1. (2) The monitor lamp output should flash to indi-
cate the position of the height sensor. The sensor
should be in the high position. A continuously
lighted monitor lamp will indicate a system failure.
Such as the compressor relay output has operated for
150 610 seconds but the height sensor did not move
to the high position within the right shock absorber).
See Diagnostic Chart 1. (3) Next the exhaust solenoid output is activated
until the vehicle is in the low position. The maxi-
mum exhaust solenoid operation time is 120 610 sec-
onds. If the expected position is not obtained, the
module ceases self-diagnostics and any further oper-
ation. The monitor lamp output is lighted continu-
ously until ignition is cycled from OFF to ON or 60
6 1 minutes has elapsed after ignition is turned off.
See Diagnostic Chart 4. (4) The monitor lamp should flash to indicate the
height sensor is in the low position. A continuouslyFig. 7 Control Module Connector
Fig. 8 Diagnostic Test Pin Location
Ä SUSPENSION AND DRIVESHAFTS 2 - 65